Armrest having armrest bun and method of manufacture

ABSTRACT

An armrest bun. The armrest bun inserts within an armrest to provide cushioning. The armrest bun includes a support substrate and a poured foam layer. The bun inserting within a cavity of the armrest. The foam layer shaped to match the armrest cavity to limit dead-spots. The bun can be manufactured by position a support substrate in a pouring tool. Foam is poured into a cavity of the pouring tool. The poured foam solidifies to bond to the support substrate. The bun can then be inserted into the armrest.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 10/800,548filed Mar. 15, 2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to armrests of the type having an armrestbun. The armrest bun inserts within the armrest for cushioning.

2. Background Art

U.S. Pat. No. 6,213,538 relates to an armrest and method formanufacturing the same. The '538 patent discloses an armrest bun. Thearmrest bun includes a die-cut foam pad adhered to a plastic substrate.The substrate and foam are inserted within the armrest to providecushioning thereto.

Armrests are manufactured in many different sizes and shapes. Pastarmrests were typically rectangular in shape for ease of manufacturing.Newer armrests may include curvatures and tapers. The new shaping ismore aesthetically appealing and can provide better comfort. The foam inthe armrest bun must closely match the armrest shaping.

Dead-spots appear on an outer surface of the armrest if the foam failsto closely match the shaping of the armrest. The dead-spots are hollowsor gaps at non-cushioned portions in the armrest. The dead-spots appearas indents on the surface of the armrest. The lack of cushioning at thedead-spots interrupts the feel and texture of the armrest.

The dead-spots can be limited by closely shaping the foam to match theshape of the armrest. The matched foam snugly fits into the armrest toprovide proper cushioning. The snug fit cushions the outer surface ofthe armrest to eliminate the dead-spots. The difficulty lies in shapingthe foam to match the armrest, and doing so in a cost-efficient manner.

The inventors of the present invention have identified a manufacturingproblem with the '538 patent. The problem relates to shaping the die-cutfoam disclosed by the '538 patent to properly fit the armrest. Shapingthe foam with the desired shaping, which may include curvatures andtapers, requires a number of cutting operations. Multiple workstationsmay also be constructed to focus on different cuts. One station may beneeded to cut a blank, another station may be needed to cut a curve onthe blank, and yet another station may be needed to cut a taper on theblank.

It is expensive for a manufacturer to spend time performing multiplecutting steps. It is also expensive for a manufacturer to purchase andmaintain the various cutting tools and workstations. Accordingly, it isdesirable to provide a more cost-effective method for manufacturing thearmrest buns.

SUMMARY OF THE INVENTION

The inventors of the present invention have developed a morecost-effective method for manufacturing an armrest bun that overcomesthe above-identified deficiencies of the prior art.

The present invention contemplates a number features, including anarmrest bun having a support substrate and a foam layer. The foam layeradheres to the support substrate and inserts within an armrest. The bunis preferably sized and shaped to provide cushioning support to thearmrest. The bun preferably supports the armrest such that dead-spotsare limited and the armrest has a smooth and uninterrupted texture.

In one aspect of the present invention, the foam layer is a tapered andcurved to match a tapered curvature of the armrest. The foam layerpreferably comprises a poured foam. The foam can be poured into a moldcavity to adhere to the support substrate. The cavity can be sized andshaped to provide the desired taper and curvature. The poured foamsolidifies in the cavity to take the shape of the tapered and curvedcavity. The solidified foam matches the taper and curvature of thearmrest to provide a snug fit therebetween.

In one aspect of the present invention, the support substrate includes achannel. The channel rides within a shoulder of a support substrate inthe armrest cavity to position the support substrate thereto. Thesupport substrate can further include a ridge. The ridge can cooperatewith a lip on an outer skin of the armrest to position it thereto. Thesupport substrate can further include a locating face proximate the lipon the outer skin. The locating face corresponds with a bottom-outposition of the lip to indicate proper assembly of the outer skin to thesupport substrate.

In one aspect of the present invention, the support substrate includesan elongated prong. The prong can extend relative to a vertical wall ofthe support substrate. The foam material can form on a top and/or bottomof the prong. The prong can include apertures through which the pouredfoam can flow for bonding. The prong can include a prong ridge to limitslippage of the foam layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a door assembly in accordance with the presentinvention;

FIG. 2 illustrates a cross-sectional view of an armrest shown in FIG. 1along the line 2-2;

FIG. 3 illustrates a perspective view of an armrest bun in accordancewith first embodiment the present invention;

FIG. 4 illustrates a perspective view of an armrest bun in accordancewith a second embodiment of the present invention;

FIG. 5 illustrates a perspective view an armrest bun in accordance witha third embodiment of the present invention; and

FIG. 6 illustrates a pouring fixture in accordance with the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a door assembly 10 in accordance with the presentinvention. The door assembly 10 includes an armrest 14 commonly used inautomotive vehicles. The present invention is not limited to theembodiment shown in FIG. 1. The present invention contemplates a numberof embodiments, including non-automotive applications, such as boats,trains, planes, and the like.

The armrest secures to a door panel 18 by a fastener or other means toprovide a resting location for an occupant in a vehicle. The armrestincludes an arcuate or curved-out surface and a tapering edge to providean aesthetically appealing and comfortable armrest. The curvature andtaper generally define an outward appearance shape for the armrest 14.Other shapes and configurations may also be used without deviating fromthe scope and contemplation of the present invention.

The armrest 14 includes an armrest bun 22. The armrest bun 22 insertswithin a cavity of the armrest 14 to provide cushioning thereto. Thearmrest bun 22 inserts at a lateral rearward end of the door 18. Thepresent invention contemplates alternative designs that may includeadditional buns 23. The bun 22 and/or additional buns can be inserted atdifferent areas on the armrest 14.

FIG. 2 illustrates a cross-sectional view of the armrest 14 shown inFIG. 1 taken along line 2-2. The armrest 14 includes an outer skin 26that wraps around a first substrate 30. The outer skin 26 can be moldedto or separately attached to the first substrate 20. The outer skin 26and first substrate 30 define a first armrest cavity. The outer skin 26preferably comprises a flexible material to facilitate its comfort. Thefirst substrate 30 is preferably a plastic, metal, or similar rigidmaterial.

The outer skin 26 includes a first lip 34 that wraps around an end 38 ofthe first substrate 30 to position it thereto. The lip 34 helps securethe outer skin 26 to the first substrate 30 to limit the appearance of agap between the outer skin 26 and the door 18. The first substrate 30includes an angle flange 42 to tighten the armrest 14 to the door 18.The angled flange 42 enters through an opening 44 in the door panelduring assembly. The angled flange 42 pulls on the first substrate 30during insertion of the armrest 14 to force the armrest 14 against thedoor 18, thereby limiting gap formation between the outer skin 26 andthe door panel 18. A fastener 46 secures the angled flange 42 to thedoor panel 18.

The armrest bun 22 includes a second substrate 50 and a foam layer 56.The foam layer 56 adheres to the second substrate 50 for insertionwithin the armrest cavity defined by the first substrate 30 and theouter skin 26. The foam layer 56 is shaped to match the shaping of thearmrest 14 so that it snugly fits within the armrest cavity and provideseven support throughout. The close matching of the foam layer 56 to theshaping of the armrest cavity limits dead-spots as most, if not all, ofthe armrest cavity is supported by the foam layer.

The second substrate 50 includes a channel portion 60. The channelportion 60 cooperates with a shoulder 64 of the first substrate 30proximate an opening to the armrest cavity. The channel 60 rides withinthe shoulder 64 to position the second substrate 50 thereto. A detent 66is located at one end of the channel 60. The detent 66 cooperates withan aperture 68 in the first substrate 30. The detent 66 catches withinthe aperture 68 to secure the bun 22 therein. The detent 66 alsoprovides a means for determining that the bun 22 has been properlyinserted into the armrest cavity, as it limits retraction of theinserted bun 22 when locked.

The second substrate 50 includes a ridge 72 for receiving a lip 76 ofthe outer skin 26. The lip 76 catches on the ridge 72 to position theouter skin 26 thereto. The ridge 72 limits the outer skin 26 fromflexing away from the second substrate 50. Preferably, the outer skin 26is stretched to fit over the ridge 72 so that force is applied to anunderside of the ridge 72 to further secure the outer skin 26 thereto.

The second substrate 50 includes a locating face 80 proximate the lip76. The locating face 80 is positioned at a bottom-out point of the lip76. The lip 76 rests on the locating face 80 if the skin 26 is properlyassembled. The lip 76 is offset from the locating face 80 if the skin 26is improperly assembled.

FIG. 3 illustrates a perspective view of the armrest bun 22 inaccordance with a first embodiment of the present invention. Theperspective view shows the foam layer 56 in phantom to draw out thefeatures of the second substrate 50 in more detail. The locating face80, the ridge 72, and the channel 60 are shown. A funnel 84 is alsoshown. The funnel 84 is an aperture in the second substrate 50 throughwhich foam is poured. The pouring of the foam is described below in moredetail.

FIG. 4 illustrates a perspective view of an armrest bun 90 in accordancewith a second embodiment of the present invention. The bun 90 includesan elongated planar surface or prong 94. The prong 94 projects from atop portion of the channel 60. The prong 94 provides further support forthe foam layer 56 shown in phantom. The prong 94 is shown as relativelyplanar, however, it can be arched to facilitate shaping the foam layer56. The prong 94 includes a ridge 96. The ridge 96 is an optionalfeature that the foam layer 56 can bond with to prevent slippage of thefoam 56.

FIG. 5 illustrates a perspective view of an armrest bun 100 inaccordance with a third embodiment of the present invention. The bun 100includes two elongated prongs 102 and 106 that project from a verticalwall 110 of the second substrate. Each prong 102 and 106 includes one ormore apertures 112, 114, 116 and 118 through which the foam is poured.The foam bonds within the apertures 112, 114, 116 and 118 to preventslippage of the foam layer 56. Similar prongs could be included withinthe bun 90 shown in FIG. 4.

FIG. 6 illustrates a pouring fixture 130 in accordance with the presentinvention. The pouring fixture 130 includes a fixture 134 for receivingthe second substrate 50 and a cavity 136. The cavity 136 is shapedaccording to the desired shaping of the foam layer 56. The cavity 136can include any shape and configuration, including that which matchesthe curvature and taper of the armrest cavity.

The second substrate 50 is positioned within the fixture 134 and a lid140 closes to secure it therein. Foam material is poured through anopening 142 in the lid. The opening 142 aligns with the funnel 84 sothat the foam pours through the funnel 84 into the cavity 136. The foamis poured and solidifies. The solidified foam bonds chemically andmechanically to the second substrate 50 to form the buns shown in FIGS.3-5. The foam could also be injected directly into the cavity through achannel to eliminate the need for a funnel 84 in the second substrate50.

The foam material preferably comprises any suitable foam material thatmeets the density and rebound characteristics desired for the armrest14. The foam material can include polyurethane material. Preferably, thefoam material solidifies and bonds to the second substrate in 5-7seconds.

The time to position the second substrate, to pour the foam, to solidifythe foam, and to remove the completed bun 22 is relatively short tofacilitate large-scale manufacturing. The foam is preferably poured in asingle application to lessen processing time. The pouring fixture 130can also include multiple cavities 136 to manufacture additional buns ina single foam pour. The bun manufacturing process is cost-effective dueto the limited tooling and processing steps.

While embodiments of the invention have been illustrated and described,it is not intended that these embodiments illustrate and describe allpossible forms of the invention. Rather, the words used in thespecification are words of description rather than limitation, and it isunderstood that various changes may be made without departing from thespirit and scope of the invention.

1. A method of manufacturing an armrest bun, the method comprising:configuring a pour tool to include a cavity and a fixture, the fixtureconfigured to receive a support substrate; positioning the supportsubstrate in the fixture such that a portion of the support substrate isin communication with the cavity; and pouring a foam material into thecavity, the foam material sufficient to bond to the portion of thesupport substrate in communication with the cavity.
 2. The method ofclaim 1 further comprising defining the cavity to include a curvature,the curvature matching a curvature in an armrest cavity, the poured foamshaped by the cavity curvature so that the foam forms to match thearmrest cavity curvature.
 3. The method of claim 1 further comprisingdefining the cavity to include a taper, the taper matching a taper in anarmrest cavity, the poured foam shaped by the cavity taper so that thefoam forms to match the armrest cavity taper.
 4. The method of claim 1wherein the support substrate includes an elongated prong, and whereinthe method further comprise positioning the support substrate so thatthe elongated prong extends into the cavity, the poured foam chemicallybonding to the elongated prong.
 5. The method of claim 4 wherein theelongated prong includes an aperture, and the method further comprisespositioning the support substrate so that the aperture is positionedwithin the cavity, at least a portion of the poured foam pouring throughthe aperture and chemically bonding thereto.
 6. The method of claim 1wherein the support substrate includes a funnel, the funnel extendingfrom one side of the substrate through to an opposite side of thesupport substrate, and wherein the method further comprising positioningthe support substrate so that the poured foam pours through the funnelto reach the cavity.
 7. A method of manufacturing an armrest, the methodcomprising: pouring a foam into a shape suitable for use in the armrest;attaching the foam to a door used to support the armrest; and attachingan armrest skin over the attached foam and to the door to form thearmrest.
 8. The method of claim 7 further comprising pouring the foaminto a cavity having a shape corresponding with a curvature of thearmrest skin such that the poured foam matches the curvature of thearmrest skin.
 9. A method of manufacturing an armrest, the methodcomprising: pouring a foam material to form a foam layer; adhering thefoam layer to a substrate, the foam layer and substrate defining anarmrest bun; and inserting the armrest bun into a cavity of the armrest.10. The method of claim 9 wherein a portion of the cavity has acurvature, and the method further comprises pouring the foam material toinclude a corresponding curvature such that the inserted armrest bunsnuggly fits to the curvature of the cavity to limit dead-spots.
 11. Themethod of claim 9 wherein a portion of the cavity has a taper, and themethod further comprises pouring the foam material to include acorresponding taper such that the inserted armrest bun snuggly fits tothe taper of the first cavity to limit dead-spots.
 12. The method ofclaim 9 wherein the armrest includes a shoulder on an opening side ofthe cavity, and wherein the method further comprising positioning achannel on the substrate such that the channel mates with the shoulder.13. The method of claim 9 wherein the armrest includes a flexible skinthat includes a lip extending over an opening side of the cavity, andwherein the method further comprises positioning a ridge on thesubstrate such that the lip flexes over the substrate to catch on theridge of the inserted armrest bun so as to position the skin thereto.14. The method of claim 9 wherein the armrest includes a skin having anaperture proximate an opening side of the cavity, and wherein the methodfurther comprising positioning a detent on the substrate so as to catchin the aperture.
 15. The method of claim 9 configuring the armrest toinclude an angled flange proximate an opening in a door panel such thatan angle of the flange tightens the armrest against the door panel whenattached thereto so as to limit separation of a skin of the armrest fromthe door panel.
 16. The method of claim 9 wherein the armrest includes aflexible skin having a lip extending over an opening side of the cavity,and wherein the method further comprising positioning a locating face ofthe substrate proximate the opening side of the first cavity when thebun is inserted into the first cavity, the lip resting on the locatingface of the inserted bun if the skin is properly assembled, the lipseparated from the locating face if the skin is improperly assembled.17. The method of claim 9 wherein the substrate includes an elongatedprong extending laterally from an end of the substrate into the firstcavity, and wherein the method further comprising chemically bonding thefoam to the prong.